It must be remembered that excluding his farcical 40-second comeback victory against no-hoper Phil Lo Greco, this was his first serious fight since a brutal knockout defeat by Saul “Canelo” Alvarez in May 2016.

Yet a wobbly display against Vargas indicates the former unified champion is still clearly some way off the pace.

Khan doesn’t seem too keen on locking horns with fellow Brit and former IBF welterweight champion Kell Brook - who has repeatedly called him out for close to five years - instead setting his sights on a money-spinning showdown with a 39-year-old Manny Pacquiao.

Pacquiao, the only eight division world champion in the sport’s history, holds a version of the WBA welterweight title but is now well past his prime.

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Khan now wants a shot at Manny Pacquiao (left)

One issue surrounding a potential clash with Brook is the latter’s insistence to remain at 154 lbs, where he stepped up to in a win over Siarhei Rabchanka back in March.

But who are the current top dogs at 147 lbs?

1. Errol Spence Jr

IBF chief Spence took the title from Brook in May 2017 and doesn’t look like losing it anytime soon. A superb all-round fighter; he is a true force at the weight, unbeaten in 24 bouts and capable of producing a mean shot to the body.

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Errol Spence (right) is the best welterweight on the planet right now

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Terence Crawford (left) won the WBO championship in his 147-pound debut against Jeff Horn

2. Terence Crawford

WBO champion Crawford (33-0) stakes claim to being the world’s No.1 pound-for-pound fighter, yet he must settle for No.2 in this list due to the fact his 147 debut only came when he took Jeff Horn’s title in June. Nevertheless, the former super-lightweight king is devastatingly accurate, frighteningly powerful and quick with both hands, leaving fight fans dreaming of a unification clash with Spence.

3. Shawn Porter

The 30-year-old recently picked up the vacant WBC crown by beating Danny Garcia in New York on Saturday night, his first world title since suffering defeat to Kell Brook in 2014. Porter is an aggressive, come-forward fighter, but someway off seriously challenging the likes of Spence and Crawford.

4. Keith Thurman

28-0 Thurman toppled both Porter and Garcia before a hand injury forced him to relinquish his WBC strap in April. He remains WBA ‘Super’ champion, nevertheless, and despite being out of the ring for 18 months he is in at No.4 ahead of a potential comeback at the end of the year.

Defeat to Porter on Saturday night - in what was a close-fought contest - was a huge blow for the Philadelphian, who must now plot another route to recapturing a world title. Many feel he was unfortunate not to get the decision, however.

6. Manny Pacquiao

The legend from the Philippines will always be remembered for his unsuccessful showdown with fellow great Floyd Mayweather. He remains active and a champion at 39, however, meaning he stays in this list.

7. Jeff Horn

Horn shocked the world when he toppled Pacquiao in Brisbane back in July 2017. Yet, his reign as champion ended in a brutal defeat by Crawford almost a year later, who proved the Australian to be way out of his depth.

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Manny Pacquiao (right) may be past his best but he remains in the top 10

8. Jessie Vargas

Former WBO champion Vargas has come short in his most high-profile bouts, most notably against Pacquiao in 2016. A very technical fighter who does the basics well, but by no means a major player in the division.

9. Lamont Peterson

Recently beaten by Spence and at 34 his best years are behind him. Yet, on his day, former WBA welterweight champion Peterson is a more than able opponent for the division’s top dogs.

10. Adrien Broner

The cocksure American flirts between 147 and 140 lbs, and was handed painful defeats at the hands of Mikey Garcia and Shawn Porter. But he has held world titles in four different weight classes and could achieve a lot more with a better mindset.